feat(bigquery): Native math function annotations (#4201)

* feat(bigquery): Custom type annotations

* PR Feedback 1

Author: VaggelisD

sqlglot/dialects/bigquery.py

@@ -293,6 +293,11 @@ class BigQuery(Dialect):
     # All set operations require either a DISTINCT or ALL specifier
     SET_OP_DISTINCT_BY_DEFAULT = dict.fromkeys((exp.Except, exp.Intersect, exp.Union), None)
 
+    ANNOTATORS = {
+        **Dialect.ANNOTATORS,
+        exp.Sign: lambda self, e: self._annotate_by_args(e, "this"),
+    }
+
     def normalize_identifier(self, expression: E) -> E:
         if (
             isinstance(expression, exp.Identifier)

sqlglot/dialects/dialect.py

@@ -577,7 +577,6 @@ class Dialect(metaclass=_Dialect):
         exp.DataType.Type.DOUBLE: {
             exp.ApproxQuantile,
             exp.Avg,
-            exp.Div,
             exp.Exp,
             exp.Ln,
             exp.Log,
@@ -689,9 +688,10 @@ class Dialect(metaclass=_Dialect):
         exp.GenerateTimestampArray: lambda self, e: self._annotate_with_type(
             e, exp.DataType.build("ARRAY<TIMESTAMP>")
         ),
+        exp.Greatest: lambda self, e: self._annotate_by_args(e, "this", "expressions"),
         exp.If: lambda self, e: self._annotate_by_args(e, "true", "false"),
         exp.Interval: lambda self, e: self._annotate_with_type(e, exp.DataType.Type.INTERVAL),
-        exp.Least: lambda self, e: self._annotate_by_args(e, "expressions"),
+        exp.Least: lambda self, e: self._annotate_by_args(e, "this", "expressions"),
         exp.Literal: lambda self, e: self._annotate_literal(e),
         exp.Map: lambda self, e: self._annotate_map(e),
         exp.Max: lambda self, e: self._annotate_by_args(e, "this", "expressions"),

tests/fixtures/optimizer/annotate_functions.sql

@@ -1,5 +1,26 @@
 --------------------------------------
--- Spark2 / Spark3 / Databricks functions
+-- Dialect
+--------------------------------------
+ABS(1);
+INT;
+
+ABS(1.5);
+DOUBLE;
+
+GREATEST(1, 2, 3);
+INT;
+
+GREATEST(1, 2.5, 3);
+DOUBLE;
+
+LEAST(1, 2, 3);
+INT;
+
+LEAST(1, 2.5, 3);
+DOUBLE;
+
+--------------------------------------
+-- Spark2 / Spark3 / Databricks
 --------------------------------------
 
 # dialect: spark2, spark, databricks
@@ -69,3 +90,16 @@ STRING;
 # dialect: spark2, spark, databricks
 RPAD(tbl.str_col, 1, tbl.str_col);
 STRING;
+
+
+--------------------------------------
+-- BigQuery
+--------------------------------------
+
+# dialect: bigquery
+SIGN(1);
+INT;
+
+# dialect: bigquery
+SIGN(1.5);
+DOUBLE;

tests/test_optimizer.py

@@ -806,10 +806,10 @@ def test_annotate_funcs(self):
             load_sql_fixture_pairs("optimizer/annotate_functions.sql"), start=1
         ):
             title = meta.get("title") or f"{i}, {sql}"
-            dialects = meta.get("dialect").split(", ")
+            dialect = meta.get("dialect") or ""
             sql = f"SELECT {sql} FROM tbl"
 
-            for dialect in dialects:
+            for dialect in dialect.split(", "):
                 result = parse_and_optimize(
                     annotate_functions, sql, dialect, schema=test_schema, dialect=dialect
                 )